This invention relates to electrostatographic process equipment and, more particularly, to a web apparatus for cleaning toner and other particles from a surface of an image-bearing or other member in such equipment.
Electrostatographic process equipment produce or reproduce desired toned images on an insulated image-bearing surface by employing electrostatic charges and toner through a repeatable cycle. A typical cycle includes the steps of (1) using electrostatic charges in some manner to form an electrostatic image on the image-bearing surface; (2) developing this image with particles of toner; (3) transferring the toned image to a receiver; and (4) cleaning residual toner and other particles from the front and backside surfaces of the image-bearing member in preparation for repeating the cycle. The quality of images obtained by repeating these steps depends significantly on the ability to clean these surfaces.
The cleaning step is, therefore, very important and has led to the development of many cleaning methods and apparatus. One such method and apparatus utilizes a web of fibrous material such as paper towelling to contact and wipe residual toner and other particles from a surface of the image-bearing member.
Conventionally, this method and apparatus includes three rolls. Typically, these are a supply roll that holds and supplies unused web material, a pressure roll that presses the web material into contact with the surface being cleaned, and a take-up roll for the used web material. These three rolls usually are on three separate axes, each requiring separate mechanical supports, and sometimes even drive means, thereby adding to the complexity of the system. The pressure roll, by bringing the web material into contact with the surface to be cleaned, in addition, has a tendency for introducing undesirable normal forces into the surface, especially when the surface is the front or backside of a photoconductive belt.